The present invention relates to routing calls in a telephone network, and more particularly to methods and apparatus for routing calls in a network including the Internet.
Internet telephony is two way voice communication over a packet switched network, such as the Internet. FIG. 1 is a diagram of an Internet voice communication network including Internet telephony equipped computers 102 and 110, Internet Service Providers 104 and 108, and the Internet 106. To establish voice communication over the Internet using currently available Internet technology, each participant in a voice call must have a computer equipped for Internet access and special hardware and software supporting Internet voice communication. For example, computers 102 and 110 would require a modem, TCP/IP software, a dialer, a sound card, a microphone, and a speaker to be suitably configured for Internet telephony.
To obtain Internet telephony service using an Internet telephony equipped computer, the parties to a call, computers 102 and 110 connect to an Internet Service Provider providing access to Internet 106. Accordingly, Internet Service Provider account holders paying a flat fee for Internet access can engage in voice communication with one another over the Internet without incremental usage charges. Although the advantage of voice communication using Internet telephony according to current billing methods is the insensitivity of the cost of calls to their duration, there are several drawbacks to this approach. First, each party to Internet telephony voice communication must have a computer and it must be properly equipped for voice communication. Second, computer 110 must be connected to Internet 106 at the time computer 102 initiates a call. Third, many of the Internet telephony software packages are not compatible with other vendors"" Internet telephony software. Fourth, the sound quality of Internet telephony calls is generally worse than the sound quality of calls transmitted through the public switched telephone network (PSTN).
To address some of the limitations of providing voice communication through the Internet imposed by using the Internet and telephony-capable computer terminals, some vendors have developed Internet telephony gateways. Internet telephony gateways allow parties that only subscribe to xe2x80x9cplain old telephone servicexe2x80x9d (POTS), but do not have Internet equipped computers and an account with an Internet service provider, to talk to each other through the Internet. FIG. 2 is a network diagram of an Internet telephony service for POTS subscribers. The network of FIG. 2 includes telephone 202, PSTN 204, Internet telephony gateway 206, Internet 214, Internet telephony gateway 216, PSTN 224, and telephone 226.
Internet telephony gateway 206 includes gateway controller (GC) 208, voice translation unit (VTU) 210, and interactive voice response unit (IVR) 212. Internet telephony gateway 216 is similarly configured with GC 218, VTU 220, and IVR 222. A GC performs signaling required for call setup and call tear down between a PSTN and the Internet; accordingly a GC supports both PSTN and Internet signaling protocols. A VTU processes voice signals, which includes packetizing and depacketizing the voice data stream between the PSTN and the Internet. An IVR plays announcements to a calling or called party and collects digits entered using a telephone touch-tone (dual tone multi-frequency (DTMF)) key pad.
To establish an Internet telephony call through the Internet telephony gateway network depicted in FIG. 2, a phone call originator dials from telephone 202 a telephone number assigned to Internet telephony gateway 206 serving PSTN 204. Internet telephony gateway 206 answers the call and connects the caller to IVR 212. Internet telephony gateway 206 interacts with the caller using IVR 212 by playing announcements and collecting digits entered by the caller. Examples of information collected from the caller by IVR 212 include the telephone number of called party at telephone 226, the caller""s user identification number, and password. By analyzing the called party""s telephone number, Internet telephony gateway 206 determines the network address of Internet telephony gateway 216, which is the Internet telephony gateway providing the least cost path to the called party at telephone 226. Internet telephony gateway 206 then sends a call setup signaling request to Internet telephony gateway 216 using GC 208. Responding to the call setup request, Internet telephony gateway 216 rings telephone 226. When the called party answers telephone 226, an end-to-end communication path is established through the network between telephone 202 and telephone 226. This path includes three segments, a circuit switched path between telephone 202 and PSTN 204, a packet exchange through Internet 214 between Internet telephony gateway 206 and Internet telephony gateway 216, and a circuit switched path between telephone 226 and PSTN 224.
An advantage of using Internet telephony gateways to provide voice communication over the Internet is that such a service is integrated with the calling and called parties"" regular telephone service. Neither party requires special computer equipment or an Internet service provider account. Moreover, for one party to place an Internet voice call through the Internet using Internet telephony gateways, both the calling and called party do not have to be logged onto the Internet.
FIG. 3 is a diagram of networks for providing telephone service. Using Internet telephony gateways, telephone service carriers are beginning to offer service that allows callers a choice of voice communication through a circuit switched telephone network 312, an Internet-based packet voice network 314, or through a hybrid network including both a circuit switched telephone network and an Internet-based packet voice network 316. Points of presence (POP) 306, 308, 310, 326, 328, and 330 deployed throughout local PSTN 304 and local PSTN 332 provide access to these networks. Points of presence providing voice communication service through the Internet, i.e., POPs 308, 310, 328, and 330, contain Internet telephony gateways as described in greater detail above.
Because of the cost/performance trade-offs associated with choosing Internet-based voice communication versus circuit switched voice communication, telephone service subscribers want the ability to choose on a call-by-call basis the method of transmission of a voice call. For example, when quality of service is an overriding concern for a given call, the calling party will most likely want the call completed through a circuit switched network. When, on the other hand, price is an overriding factor, the calling party would select an Internet-based telephone service provider. Not only should a caller be able to select between Internet service and circuit switched service, but a caller should also be able to choose among several Internet-based voice communication service providers having different rate structures and having POPs closest to the called party.
Accordingly, it is an object of the invention to provide an Internet telephony routing capability that allows intelligent routing of telephone calls through Internet-based voice communication service providers when such routing conforms with caller preferences.
As previously described, the current state of the art in Internet telephony requires a phone call originator to dial a telephone number associated with the Internet Telephony gateway and subsequently interact with the gateway to enter the caller""s account number and identification number, as well as, the called party""s telephone number. This dialing procedure corresponds to the dialing procedure used for making PSTN phone calls using calling cards or debit cards. It is also an object of the invention to provide Internet Telephony users with the ease of use that is currently enjoyed by POTS users and allow a telephone service subscriber to take advantage of Internet telephony without changing their current behavior. It is an object of the invention to allow a caller to make an Internet phone call by using a phone connected to POTS and, unless the calling party is dialing from a remote phone, dialing the called party""s phone number without dialing additional access codes or having to respond to prompts.
To achieve these and other advantages and in accordance with the purposes of the invention, as embodied and broadly described, the invention includes an efficient method for automatically designating a telephone call route through a telephone network including a circuit switched telephone network (STN) and a packet switched network, such as the Internet. The method includes the steps, executed by a network element, such as a service control point (SCP), of receiving a telephone number corresponding to a called party receiving the telephone call, reviewing preference information pertaining to a calling party""s telephone service, determining from the preference information and the telephone number whether the telephone call can be routed to the called party through the Internet, and assigning a route for the telephone call through one of either the Internet or the STN to the called party based on whether the call is routable through the Internet.
The invention also comprises a network element, such as an SCP, for automatically designating a telephone call route through a telephone network including an STN and the Internet. The network element includes structure for receiving a telephone number corresponding to a called party receiving the telephone call, structure for reviewing preference information pertaining to a calling party""s telephone service, structure for determining from said preference information and said telephone number whether said telephone call can be routed to said called party through said Internet, and structure for assigning a route for the telephone call through one of either the Internet or the STN to the called party based on whether the call is routable through the Internet.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.